chg: script run dumptoemul - better fail messages

client/scripts/dumptoemul.lua

@@ -14,7 +14,7 @@ example = [[
     script run dumptoemul -i dumpdata-foobar.bin
 ]]
 usage = [[
-script run dumptoemul [-i <file>] [-o <file>]
+_script run dumptoemul [-i <file>] [-o <file>]
 
 Arguments:
     -h              This help
@@ -108,8 +108,11 @@ local function main(args)
     if infile == nil then
         return oops('Could not read file ', input)
     end
-    local dumpdata = readdump(infile)
+ 
+   local dumpdata = readdump(infile)
     -- The hex-data is now in ascii-format,
+   if dumpdata == NIL then return oops('Dumpfle not loaded') end
+
 
     -- But first, check the uid
     local uid = string.sub(dumpdata, 1, 8)
@@ -117,6 +120,8 @@ local function main(args)
 
     -- Format some linebreaks
     dumpdata = convert_to_emulform(dumpdata)
+   if dumpdata == NIL then return oops('Dumpfle not loaded') end
+
 
     local outfile = io.open(output, 'w')
     if outfile == nil then